What is Fest3D?

Fest3D is a software tool capable of analyzing complex passive microwave components based on waveguide and coaxial cavity technology. It is fast and delivers high accuracy compared to software tools based on full-segmentation techniques. This suite offers all the capabilities needed for the design of passive components such as optimization and tolerance analysis. Moreover, Fest3D advanced synthesis tools can be used to design bandpass, dual-mode, and low-pass filters from user specifications.

Fest3D is based on the electromagnetic (EM) simulation integral equation technique efficiently solved by the Method of Moments. In addition, the Boundary Integral-Resonant Mode Expansion (BI-RME) method is employed for extracting the modal chart of complex waveguides with arbitrary cross-sections. The successful combination of such methods ensures a high degree of accuracy and a reduction in the computational resources required (in terms of CPU time and memory).

Fest3D is an optional part of the EM simulation package CST Studio Suite and is also available as a stand-alone product.

Radiofrequency Filter Analysis and Design with Fest3D

Analysis Method
Filter Design

Analysis Method

The Fest3D analysis method uses a multimode equivalent network representation of waveguide junctions. Fest3D solves each element in the complete circuit with the best available method, ensuring both efficiency and accuracy. On this basis, Fest3D can simulate complex passive devices quickly (in the order of seconds or a few minutes). In contrast, general-purpose software (based on segmentation techniques such as finite elements or finite differences) can take hours to simulate the same structure.

Furthermore, the employed integral equation technique extracts part of the frequency-dependent computations, resulting in a short computational time per frequency point. Engineers benefit from this advantage, particularly for high accuracy requirements, which corresponds to considering many electromagnetic modes when analyzing the component.

Fest3D helps analyze components such as:

Filters (combine filters, interdigital filters, waffle-iron filters, dual-mode filters, band-stop filters, ...)
Multiplexers (Diplexers, OMUXs, ...)
Feeding networks
Couplers and Polarizers
OMTs